Telescope.



Patented .lune I0, |902. A. A. COMMUN.

TELESCOPE.; (Applicatiop med may 11, 1901.)

(No Model.)

UNITED STATESv PATENT O'EEICE.

ANDREWV AINSLIE COMMON, OF EALING, ENGLAND.

TELESCOPE.

SPECIFICATION forming part of Letters Patient No. 702,048, dated June10, 1902.

' Application lad May 11, 1901. Serial No. 59.717. (No model.) 'i iscope with the dew-cap removed. Fig. 2 is a longitudinal verticalsection of the same.

Fig. 3 is a plan view of the eyepiece-tube, and

Fig. 4 is a similar View of that part of the eyepiece carrying the thirdand fourth lenses or the erector detached.

a is the main tube of the telescope, provided internally with a featheror key b, the use of which will bepresently explained.

c is the object-glass, which is carried by one end of a tube d, screwedinto the end of the main tube a. The other end of this tube d carriesthe cross-wires e, which are thus rigidly mounted with respect to theobject-glass, in the principal focus of the same, the tube being of sucha length as to permit of this, for with such a low power as is found tobe most suitable for sighting purposes no sensible parallax isintroduced for any objects over a few yards distance. The constructionof this tube, the mode of effecting the collimation of theobject-glasses, and the mode of securing the cross-wires form no part ofthe present invention, and further reference need not therefore be madeto these points, as they may be carried out in any convenient manner. v

To the open end ofthe tube a the eyepiece is secured. y Thisy eyepieceis composed of three parts-namely, a tube f, an eyepiece proper, g, andan erector h. The distance between the piece g and the erector h will bemade to change, accordi-ng to the focus "required, by turning the pieceg from the outside, which operates, by means of a quickthreaded screw orother` suitabledevice, the erector h, moving it in or out, so as to varytheir relative positions along the axis, thus v obtaining the necessaryoptical correction for dierence ofsight. I

Toone end of the tube f isv secured in any convenient manner a cylindert', externally of which is cut a spiral groove or quickthreaded screwj.Mounted upon this cylinder d is a second cylinder k, hereinafter termedthe carrier, which carries internally a projecting piece or pin l, whichworks in the groove The carrier lc is slotted at fm and into this slotthe feather b on theniain telescope-tube a enters, soas to prevent thecarrier 7c from turning around when in use. It will thus be seen that byturning the tube f with its cylinder rl, Fig. 3, `the carrier la, Fig.4, (with the erector h, which it carries,) will by reason of the pin orprojecting piece Z, working in the groove j of cylinder t', be drawn inor pushed out, as the case may be, thus varying the distance between theerector and the eyepiece proper, g.

The eyepiece g consists of an extension of `the tube f, having anexternal roughcned portion. and an eye-shield and carries internally theproper lenses.

The eyepiece g has a beveled portion n, which is marked olf with a scale(see Figs. 1

Yand 3) and fits against the end of the tube of.

The eyepiece g and the tube f are secured together in any suitablemanner, as by sweatsoldering the latter into the former, and the two areconnected with the tube a, so as to be capable1 of turning therein, butas to be confined longitudinally thereto,by means of a ring o, which issecured within the tube a, by screws s between a shoulder formed on theeyepiece and a ring p, which-is screwed onto the tube f. A covering-ringq is represented attached to the outside of the tube a, carrying apointer or mark by which the amount of rotation necessary to get therequired focus is indicated, so that any person appointed to sight thearm will be able to focus the telescope to what he knows is his sightnumber.

Y r is a device for letting air into the telescop and constituting whatI term a breathinghole.l The device consists of a little box to receivea filtering medium with suitable openings and closedA by a smallperforated plug or in any other convenient manner.

`The joint where the eyepiece-tube g turns in the ring o can be groundin so as to be airtight. The main tube a may be turned accuratelycylindrical to fit the sighting apparatus or it may have any suitablefitting for the purpose.

To Work the apparatus, lthe main tubea will be held firmly by thefitting by which the telescope is secured to the gun or by, say, theleft hand, and by means of the roughened part the eyepiece Will beturned with the other hand. The turning movement will rotate the groove7', and thus draw in or push out, as the case may be, the carrier 7swith the erector h, thus varying the distance between the eyepiece andthe erector and obtaining the required focus, the number of whichindicated by the scale may be noted for future use by the same person.

What I claim as my invention, and desire to protect by Letters Patent,is as follows:

In a telescope, the combination of a main tube, an object-glass fixed-atone end of said tube, an eyepiece fitted, to turn without movinglongitudinally in the opposite end of said tube, an erector, a carrierconsisting of a cylinder in which the erector is fixedly secured andwhich is fitted Within the main tube and slotted longitudinally,afeather secured Within the main tube and entering the longitudinal slotin the carrier, a tube connected with the eyepiece to turn therewithwithout moving lengthwise relatively thereto and having on its exteriora spirally-grooved cylinder which is fitted to turn within the carrier,and a piece projecting from and Within the carrier and entering thespiral groove of the latter cylinder, all substantially as and for thepurpose herein described.

In testimony whereof I have signed my name to this specification in thepresence of the two subscribing witnesses.

ANDREV AINSLIE COMMO N.

Vitnesses:

H. E. NEWTON, L. N. REDDIE.

